1. Technical Field
The present invention relates to a printing apparatus.
2. Related Art
A dot impact printer is known as one example of various kinds of conventional printing apparatuses. As disclosed in JP-A-2004-322463, a dot impact printer prints images by striking a number of recording wires onto a sheet of print target medium so as to record dot pattern thereon while scanning (i.e., moving) a carriage, which has recording heads mounted thereon, in the axial direction of a carriage axis.
The dot impact printer described in JP-A-2004-322463 (refer to abstract thereof) changes the accelerated velocity of the carriage during acceleration and deceleration thereof depending on the characteristic value of its operating environment. That is, in accordance with the environmental characteristic value, the disclosed dot impact printer changes the accelerated velocity of the carriage that is applied during acceleration up to the point at which the moving speed of the carriage reaches a predetermined value and the accelerated velocity thereof that is applied during deceleration from the point at which the carriage moves at the predetermined speed till it stops. By this means, the related-art dot impact printer described in the above publication achieves high-precision printing depending on use environment.
As described above, the related-art dot impact printer disclosed in the above publication changes the accelerated velocity of the carriage during acceleration and deceleration thereof depending on the characteristic value of its operating environment. Therefore, under a given set of circumstances, the carriage moves in a main scan direction constantly with the same accelerated velocity. For this reason, disadvantageously, the carriage is susceptible to intense vibration always at the same time after the start of its scanning movement, that is, when the forced vibration frequency of a carriage driving motor coincides with the resonance frequency of the dot impact printer. It is desired to provide a technical solution to the problem of uneven printing, which could occur when the carriage is vibrated intensely during the execution of printing. One conceivable solution for prevention of uneven printing is, for example, to accelerate and decelerate the carriage in a “no-ink-discharge” state. However, if such an approach is taken, a sufficiently wide space is required to secure the scanning range of the carriage.